Specify a payload contract
Separate required fields, allowed values and cross-message rules.
Python and data workflows · EDITION 1.0.0
Design and Test API Data Contracts
Build an offline contract audit for fictional request and response envelopes, then inspect compatibility risks that a version label cannot resolve.
By Sanjaay Gowda T S · For python developers, data integrators and analysts working with api payloads.
You need: Basic Python and familiarity with JSON objects; Python 3.10+ and a terminal for the optional companion
Runtime and hardware details
Python 3.10 or later and a terminal. The supplied project runs locally and uses the Python standard library.
No model, API key, cloud account or network calls are used by the companion.
Basic Python and familiarity with JSON objects; Python 3.10+ and a terminal for the optional companion.
Full setup and scope ↓$2.99USD · one-time purchase
Prepared with AI assistance. Independent human technical, editorial and assistive-technology reader review remains pending. Automated checks and agent review are not certification.
PDF + EPUB + companion project. Any applicable tax is shown at checkout. Single-reader ebook terms; companion code is MIT licensed.
TRY THE FREE SAMPLE
See how the guide teaches.
Read 7 sample pages to explore the introduction, first chapter and teaching approach before you choose the complete edition.
Read free sample PDF · No checkout required
WHAT YOU WILL LEARN
Understand each part.
Inspect every boundary.
Explain failures
Audit fictional envelopes with stable IDs and actionable issue codes.
Review compatibility
Compare producer and consumer promises under an explicit change policy.
INSIDE THE BOOK
9 focused chapters.
- Define the boundary and consumer promise
- Specify fields, absence and allowed values
- Validate request and response together
- Design errors that can be acted on
- Separate payload validity from HTTP behavior
- Review version compatibility in both directions
- Run the offline contract audit
- Build a consumer-focused regression suite
- Maintain contracts and plan a migration
Your download includes
- 21-page tagged PDF with linked contents
- Reflowable EPUB for ebook readers
- Local Python project, fictional input, recorded expected JSON output and 17 companion tests
- 3 explanatory diagrams
- 9 chapters with exercises and worked answers
Before you begin
Python 3.10 or later and a terminal. The supplied project runs locally and uses the Python standard library.
No model, API key, cloud account or network calls are used by the companion.
Learning prerequisites: Basic Python and familiarity with JSON objects; Python 3.10+ and a terminal for the optional companion.
Prepared with AI assistance. Independent human technical, editorial and assistive-technology reader review is pending.
The included examples are synthetic teaching material. Model access, software subscriptions, hosting, ongoing updates and consulting are not included.
CLEAR EXPECTATIONS
Before you buy.
What will I build?
Build an offline contract audit for fictional request and response envelopes, then inspect compatibility risks that a version label cannot resolve. The local companion uses fictional teaching fixtures. Project limits: no HTTP status/headers, authentication, authorization, persistence, idempotency, retry, network, nested schema or real consumer compatibility tests. Passing structural checks does not prove business correctness or safe deployment.
What was tested?
The 17 companion tests passed on the packaged project. The supplied fictional fixture produced its recorded expected JSON output. EPUBCheck reported no errors or warnings; DAISY Ace and PDF/UA automated checks passed. These local teaching checks are not production accuracy claims or certification. Independent human technical, editorial and assistive-technology reader review remains pending.
How do I get the files?
Complete the secure Lemon Squeezy checkout to access the PDF, EPUB and companion ZIP. Keep your receipt and download access private. This is a one-time purchase of edition 1.0.0; ongoing updates and consulting are not included.
Can I share the book or the companion code?
The full ebook is licensed to one reader. The labelled free sample may be shared unchanged. The companion project is MIT licensed and may be adapted or shared with its licence notice. See the exact ebook terms.
Validate envelopes, preserve consumer promises, and make change policies explicit
One book. A complete learning project. Evidence you can inspect.
AI-assisted · Independent human review pending
$2.99USDBuy ebook